escitalopram
Meaning of escitalopram: The mirror image half of an older drug, isolated because that half carries nearly all of the activity while its twin adds little.
Definition of escitalopram
Escitalopram is a prescription antidepressant in the class known as selective serotonin reuptake inhibitors. It slows the reabsorption of serotonin by the nerve cells that release it, leaving more of the messenger available between cells. It is prescribed for major depressive disorder and for generalized anxiety disorder, taken once daily over months or longer.
What makes it different from citalopram?
Many molecules exist in two forms that are mirror images of each other, like a left and a right hand. The two are built from the same atoms but cannot be superimposed, and a receptor, which has a shape of its own, may accept one and largely ignore the other. Citalopram is an equal mixture of both forms. Escitalopram is the single form that does the work, separated out and sold on its own.
| Aspect | Escitalopram | Citalopram |
|---|---|---|
| Composition | One mirror form only, the active one | An equal mixture of both mirror forms |
| Amount needed | Roughly half the milligram figure for a comparable effect | Higher, since half the content contributes little |
| Interchangeable | No; the numbers on the two labels do not correspond | No |
Mistaking one for the other because the names look alike is a recognized source of prescribing error, which is why the full name is written out rather than abbreviated.
What is it prescribed for?
Its approved uses are depression and generalized anxiety disorder, and like other drugs in its class it is also used for panic disorder, social anxiety and obsessive compulsive disorder. Choosing between one SSRI and another rests less on differences in effectiveness, which are small across the class, than on side effect profile, interactions with other drugs and how the individual responds. It is available as a generic, which is identical in active ingredient to the branded product.
What happens over the first weeks?
The chemical effect on reuptake begins immediately, but the change in mood does not. Improvement usually emerges gradually across several weeks, and the early period is when physical effects are most noticeable: nausea, headache, disturbed sleep, drowsiness and sexual side effects are the ones most often reported, and several of them ease with time. Escitalopram can lengthen a particular interval on the heart tracing at higher amounts, which is why it is used cautiously alongside other drugs that do the same. Stopping abruptly after a long course is associated with dizziness, irritability and sensory disturbances, an effect of the class rather than a sign of dependence, and any side effect pattern is weighed against the condition being treated.
Also known as
Used in a sentence
The patient was started on escitalopram for treatment of generalized anxiety disorder.
Good to know
Escitalopram is the single active mirror form of citalopram, a closely related but distinct SSRI, and the two medications are not interchangeable milligram for milligram despite the similarity in name.